Fluconazole loading dose pharmacokinetics and safety in infants.

BACKGROUND: Invasive candidiasis is a leading cause of morbidity and mortality in critically ill infants. Prompt administration of fluconazole and achievement of the therapeutic target (area under the curve 0 to 24 hours >400 mg*h/L) improve outcomes in candidemic patients. A loading dose of fluconazole is advised for older patients but has not been evaluated in infants. We sought to determine the pharmacokinetics and safety of a fluconazole loading dose in infants at risk for invasive fungal infection. METHODS: We enrolled 10 hospitalized infants <60 days old with suspected systemic fungal infection in this open-label study; 9 received a 25-mg/kg fluconazole loading dose followed by a maintenance dose of 12 mg/kg every 24 hours for 4 additional days. Plasma samples were obtained following the loading and steady-state doses (doses 3-5). We used a 1-compartment model to fit the data to estimate pharmacokinetic indices. RESULTS: Data from 57 drug concentrations obtained from 8 infants (median postnatal age, 16 days [interquartile range, 13-32] and median gestational age, 37 weeks [35-38]) showed that the median fluconazole area under the curve 0 to 24 hours (mg*h/L) in this population was 479 (347-496). Of the 8 infants who received the loading dose, 5 (63%) achieved the therapeutic target on the first day of dosing, and all infants achieved a fluconazole 24-hour trough concentration >8 μg/mL. No adverse events were thought to be related to fluconazole therapy. CONCLUSIONS: A loading dose of fluconazole (25 mg/kg) was safe in this small cohort of young infants and achieved the therapeutic target more rapidly than traditional dosing.

Duke Scholars

Author Phillip Brian Smith Pediatrics, Neonatology

Author Christoph Paul Vincent Hornik Pediatrics, Critical Care Medicine

Author Michael Cohen-Wolkowiez Pediatrics, Infectious Diseases

Author Daniel Kelly Benjamin Jr. Pediatrics, Infectious Diseases